Safety device



April 5, 1949.. J. 1.. BAKER 2,466,355

SAFETY DEVICE Filed Nov. 14, 1946' 2 Sheets-Sheet 1 HOTORLINE 7 M /Z 'DONTROLLINE{ .Df

J. L. BAKER SAFETY DEVICE April 5, 1949.

2 Sheets-Sheet 2 Filed NOV. 14, 1946 im 1: Jesse/L Bake]; I

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Patented 194 9 UNITED STATES PATENT OFFICE 2,466,855 SAFETY DEVICE Jesse L. Baker, Radtord, Va. Application November 14, 1946, Serial No. 709,816. 4 Claims. (01. 177-311) The present invention relates to a safety device for industrial machinery and more particularly to a safety appliance to remind the operator of the machine to put on the required protective device before starting the machine and also to prevent the operation of the machine until the protective device has been removed from the machine.

It is well known that it is dangerous to operate standard types of machinery without the pro tection afforded by suitable protective devices such as gloves, helmets or the like. For example, operators of grinding machines should wear safety goggles to protect the eyes from possible serious injury. However, operators of machines of this type are frequently injured because of failure to use safety goggles.

An object or the present invention is to provide a machine of the type described with a signal to warn the operator immediately prior to starting the machine to use the required device.

Another object of this invention is to provide a machine of the character described with means to support the required protective device, the support serving as a switch to prevent operation of the machine until the protective device is removed, and to simultaneously shut 01f the warning signal.

Yet a further object of my invention is to provide a safety device for industrial machinery which is simple both in construction and operation and which can be cheaply and easily manufactured.

With these and other objects in view, the invention broadly embraces incorporating with a machine of the type described, a warning signal and a support for the required protective device both of which form a part of the electrical circuit of the motor that drives the machine. When the operator attempts to start the machine by closing the starting switch of the electrical or gasoline power unit the circuit to the warning signal is completed. However, the circuit to the power unit remains open until the protective device is removed from the support. After the protective device is removed, a movement of the support closes the circuit to the power unit and breaks the circuit to the signal device. This arrange- In the drawings in which the same or similar reference numerals apply to similar parts:

Figure 1 is an elevational view of a grinding machine embodying the present invention.

Figure 2 is a transverse sectional view taken through the safety device and showing a pair of protective goggles in position on the supporting arm. a

Figure 3 is a view taken along the line 33 of Figure 2 looking in the direction of the arrows.

Figure 4 is a diagrammatic representation of the electrical circuit used for actuating the device shown in Figures 1 to 3 inclusive. 1

Figure 5 is a diagrammatic showing of a modified type of electrical circuit.

For the purpose of illustrating the invention there is shown in the drawings an electrically driven grinding machine of standard construction I!) equipped with a safety device ll mounted thereon, adjacent a motor l2. A metal housing I3 forms a part of the device II and is supported above the machine on standards I4. As shown in Figure 2, an opening I5 is provided in the housing which is closed by a transparent panel l6 held in position by a frame ii. If desired, suitable indicia l8 may be provided on the panel IE to serve as a reminder or warning. An electric lamp I9 of conventional construction is mounted within the housing l3 adjacent the opening I 5 to light the transparent panel l6. As best shown in Figures 2 and 3, the front wall of the housing I3 is further provided with a vertically extending slot 20 through which extends a lever arm 2|. A hook-like portion 22 is formed at the outer end of the arm, to support safety goggles '23. The other end of the arm 2| is approximately triangular in shape and is pivoted on a stud 25 secured to the housing. This stud has a threaded end (not shown) and is secured by a nut and washer assembly 26 which permits the arm to be removed from the stud for repair or replacement purposes.

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The triangular portion of the arm 2| supports a pair of conventional mercury switches 28 and 29 which are attached to opposite sides of the arm by brackets 30. The switch 28 is connected to the electrical circuit by leads 3| and 32. The switch 29 is connected to the circuit by lead 33 and to one terminal of the lamp l9 by lead 34. The other terminal o the lamp is linked to the circuit through lead 25. Insulated conduit 25 encloses the leads 2| and II and a similar conduit 51 protects lead 22. These conduits enter the housing I! through an insulated bushing 38.

Aspring is tensioned between an extension ll of the arm 2| and a pin 42 mounted within the housing. The spring 40 is of sufllcient strength to move the arm 2| about the pivot 25 when the goggles 22 are removed from the hook In Figure 4 is shown an electrical circuit embodying the present invention. In this form the-motor |2 of the three phase type is connected to a source of electrical energy 50 through lines ll, 52 and 53. These lines are broken by switches 54, 55 and 56 which are actuated by a relay 51. When the goggles 23 are on the hook 22 and start button 58 is depressed, the circuit to the relay 5! forth in the annexed claims.

cannot be completed due to the position of the mercury switches 28 and 29. However, the circult to the signal lamp l9 will be completed through start button 58, line 59, stop button 80, line 6|, switch 29, light i9 and lead 62 to the source 50. Therefore, when the start button 58 is depressed, the operator is warned by the illumination of the lamp l9 that the goggles 23 have not been removed from the arm 2|.

Upon removal of the goggles from the hook 22, the spring 40 will move the arm 2| about the pivot 25 thereby changing the position of the mercury switches 28 and 29. When the start button 58 is again depressed, current will flow through button 58, line 59, lead 63, mercury switch 29, switch 28, coil 64 of the relay 51 and line 65 to the source 50.

This energization of the relay 51 will move the switches 54, 55 and 56 to complete the circuit to the motor |2 through the lines 5|, 52 and 53. A switch 69 operates in conjunction with the switches 54, 55 and 56 to close contacts I0 and 1|, to maintain the completed circuit whenthe start button 58 is released. As a result, energy will be supplied to the motor l2 until the stop button Bil is depressed to open the circuit to the relay 51.

In this connection, the switch 29 and the stop button 60 are connected in parallel and therefore, unless the arm 2| is returned to the position shown in Figure 2, the circuit cannot be broken by pressing stop switch 60. This feature is important in that the return of the arm can be most readily accomplished by replacing the goggles on the hook 22. As a result, the goggles will be replaced and be available for the next operation of the machine. I

In Figure 5, a modified circuit having a single mercury switch 80 is illustrated. In this circuit current will flow from a supply source 8| through line 82, light l9, mercury switch 80 and lead 83 back to the source 8|, when the start button is depressed. Upon removal of the goggles, the tension of the spring 40 will raise the arm 2| thereby changing the position of the switch 80. As a result, current will be supplied to the motor M through line 82, switch 80 and line 83 to the source of supply 8|.

From the foregoing description, it is readilyapparent that I have provided a safety warning system for industrial machines which will remind the operator to don his protective apparel before the machine is started. Moreover, the motor cannot be started-until the protective appliance has been removed from its support on the machine at which time the warning signal is cut out.-

While the invention has been described with reference to specific embodiments thereof, it is to be understood that it is not to be so limited as modifications can be made therein which are within the intended scope of my invention as set I claim:

l. A safety device to warn the operator of an industrial machine to use safety protective apparel and prevent operation of the machine while the safety'apparel is in the position provided for itsstorage comprising a source of electrical energy. an electrical circuit for carrying power from the source to drive the industrial machine, pivotally supported storage means for the safety apparel, first switching means actuated by the storage means to control the delivery of power to the circuit, a signal means, a second electrical circuit carrying power to the signal means, a second switching means actuated by the supporting means to control the delivery of power to the signal means, and a starting switch to control the delivery of power to the first and second switching means, the storage means being adapted to pivot as the protective apparel is placed therein or removed therefrom to close the first switching means when the protective apparel is removed from the storage means and close the second switching means when the protective apparel is in the storage means.

2. A safety device to warn the operator of an industrial machine to use safety protective apparel and prevent operation of the machine while the safety apparel is in the position provided for its storage comprising a source of electrical power, a power circuit from a source to the machine, a relay operated switch in the circuit, a control circuit from the source to the relay, a pivotally mounted support for the protective equipment. a first switch actuated by the support controlling the delivery of power to the relay, signal means, a signal circuit connecting the control source circuit to the signal means, a double throw switch actuated by the support controlling the delivery of power tothe signal means and to the first switch, and a starting switch controlling power delivered through the control circuit, said support being adapted to rotate and close the first switch and the double throw switch to the first switch when the protective apparel is removed therefrom, and to close the double throw switch to the signal means when the protective apparel is on the support.

3. A safety device to warn the operator of an industrial machine to use safety protection apparel and prevent operation of the machine while the safety apparel is in the position provided for its storage comprising a source of electrical power for driving the machine, a power circuit delivering power from the source to the machine, a solenoid operated switch in the power circuit, a control circuit includin the solenoid operating said switch, a pivotally mounted support for the safety apparel, a first switch actuated by the support controlling the delivery of power to the solenoid, a signal means connected to the control circuit, a double throw switch actuated by the support electrically connected to the signal means and the first switch and a starting switch for closing the control circuit, said support adapted to close the first switch to the solenoid and the double throw switch to the first switch when the safety apparel is removed from the support and to close the double throw switch to the signal means when the safety apparel is on the support.

4. In an electrical circuit controlling the operation of a machine, a warning device to prevent. operation of the machine while safety appare!isinastoragepositioncomprisingasourcev off the support.

JESSE L. BAKER.

REFERENCES crrsn The following references are of record in the file of this patent:

UNITE) STATES PATENTS Number Name M smith NOV. 28, 1939 Kilpatrick June 18, 1940 

